The present invention relates to apparatus for transporting receptacles in the form of chargers or trays between spaced-apart first and second stations, and more particularly to improvements in apparatus for transporting chargers or trays of the type customarily employed for temporary storage and transport of cigarettes, filter rod sections or analogous rod-shaped articles which constitute or form part of smokers' products. Still more particularly, the invention relates to improvements in apparatus for transporting holders which removably receive filled or empty chargers or trays for cigarettes, filter rod sections or the like.
It is well known to employ chargers or trays (hereinafter called trays) for temporary storage and transport of stacks or arrays of parallel cigarettes or analogous rod-shaped articles which constitute or form part of smokers' products. As a rule, trays are filled with rod-shaped articles (hereinafter referred to as cigarettes with the understanding, however, that the trays can be filled with other types of rod-shaped articles which constitute or form part of smokers' products) during stepwise descent along the discharge end of a cigarette making or analogous machine. Reference may be had to U.S. Pat. No. 3,519,143 granted July 7, 1970 to Kochalski et al. This patent (which is incorporated herein by reference) discloses that the cigarettes can be accumulated into horizontal rows, and successive rows are thereupon introduced into the adjacent tray before the tray descends by a step so as to provide room for admission of the next row. The row-forming mechanism and/or the tray can be moved sideways (back-and-forth) during the intervals between transfers of successive rows of cigarettes into the tray so as to ensure that the cigarettes in the adjacent (superimposed) rows are staggered with reference to each other, namely, that the cigarettes which fill the tray are arranged in a so-called quincunx formation. A supply of empty trays is maintained in position of readiness at a level above the tray filling station, and the filled trays are thereupon moved to a higher level, preferably lifted to the level of the supply of empty trays, in order to introduce filled trays into an oncoming gondola of a system of circulating gondolas or analogous conveyors for transport to any one of a plurality of consuming or processing machines which are adjacent to the endless path along which the gondolas travel. The apparatus which moves filled trays from the level to which a freshly filled tray descends during downward movement along the tray filling station to the level of the supply of empty trays is desirable and advantageous because it saves to the attendant or attendants the tiresome task of lifting filled trays from a lower level to a higher level. Instead of delivering filled trays to selected processing or consuming machines, the system of gondolas can also serve for temporary or even long-lasting storage of filled trays, for example, when the processing machine or machines are out of commission while the cigarette making machine continues to turn out large quantities of cigarettes. A modern high-speed cigarette maker is capable of turning out in excess of 6,000 cigarettes per minute.
Certain heretofore known transporting apparatus which are utilized to lift filled trays from a lower level to a higher level are designed to define a single path along which a holder for trays can move upwardly to thereby deliver a filled tray to the level of the gondolas and thereupon downwardly so as to return to a position for reception of the next filled tray. Such single-path apparatus with reciprocating holder means for filled trays are incapable of handling the output of a modern tray filling machine. This is attributable to the fact that the empty holder must perform a return stroke prior to reaching a position in which it can accept the next filled tray for transport to the higher level. The time which elapses during downward movement of the unoccupied holder constitutes one-half of the total period of operation of such transporting apparatus.
In accordance with a further proposal, the apparatus for transporting trays between two different levels comprises a chain conveyor which can transport holders for empty and filled trays along an endless path. Thus, while a first holder moves a filled tray from the lower level to the higher level, a second holder which has been relieved of a filled tray can simultaneously descend from the upper level to the lower level so as to assume an optimum position for reception of the next-following filled tray. A drawback of such transporting apparatus is their complexity and high maintenance cost. This is attributable to the need for a substantial number of guide means, for means which maintain the reaches of the endless chain in parallel paths and for switchover devices. Another drawback of such apparatus is extensive wear upon their moving and adjacent stationary parts with attendant frequent and complex maintenance and repair work, and the generation of pronounced noise which is bothersome to the attendants so that the attendants must take frequent breaks.